kickdown
/ˈkɪk.daʊn/Definitions
1. noun
the act of downshifting to a lower gear, especially in a manual transmission vehicle.
“She floored it, but then had to go into kickdown to navigate the steep hill.”
2. verb
to shift (a vehicle) to a lower gear, especially in a manual transmission vehicle.
“He kicked down to second gear and accelerated up the slope.”